Field of the Invention
Embodiments of the present invention relate to electric tools to which end tools can be mounted so as to be rotatably driven for machining workpieces.
Description of the Related Art
Electric rotary tools called dust-proof board trimmers or cut-out tools are known. Such electric rotary tools may be used for various machining operations, such as cut-out operations for cutting plaster boards or the like. For example, this type of electric tool is disclosed in “INSTRUCTION MANUAL DUST-PROOF BOARD TRIMMER MODEL 3706” published by Makita Corporation in February 2006. This type of electric tool may include a drive motor for generating a rotational drive force and an output spindle (output shaft) that is rotatably driven by the rotational drive force of the drive motor. A mount mechanism may be disposed at the front end of the output spindle for mounting a machining bit (end tool). A bit selected according to the machining operation, such as a cut-out operation described above, to be performed, may be mounted to the mount mechanism. The mount mechanism may allow replacement of various bits. The replacement operation of the bit may be made by using a dedicated tool, such as a spanner, operable to loosen and fasten the mount mechanism.
In this kind of electric rotary tool, a shoe protruding from the electric rotary tool may be provided for determining a protruding distance of the bit mounted to the mount mechanism. In general, the shoe may be mounted to a housing of the electric rotary tool so as to be movable relative thereto. In addition, a rechargeable battery may be attached to the electric rotary tool for supplying an electric power to the drive motor. Therefore, a battery mount portion may be provided on the electric rotary tool for mounting the battery.
There has been a need in the art for further improving this kind of electric tool.